Completing Port Statistics scheduling in general device provider.
Adding empty shell for port statistcs discovery with bmv2 and default.p4

Change-Id: I4a333e406d6df0c6f8041d53f21cbf10f8bb9782
diff --git a/tools/test/configs/driver-cfg.json b/tools/test/configs/driver-cfg.json
new file mode 100644
index 0000000..86f0164
--- /dev/null
+++ b/tools/test/configs/driver-cfg.json
@@ -0,0 +1,14 @@
+{
+  "devices": {
+    "of:0000000000000001": {
+      "basic": {
+        "driver": "corsa"
+      }
+    },
+    "of:0000000000000002": {
+      "basic": {
+        "driver": "corsa"
+      }
+    }
+  }
+}